Switchboard-plug.



M. A. JANBS. SWITOHBOABD PLUG. APPLICATION FILED NOV. 13, 1913.

1,104; 1 95. Patented July 21, 19m:

3 n ueulioz alike one A UNITED STATES PATENT OFFICE.

MARTIN A. JANES, OF NORTHFIELD, MASSACHUSETTS.

SWITCHBOARD-PLUG.

I Specification of Letters Patent.

- and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to a new anduseful improved switchboard plug.

Heretofore in removing and replacing the braided cord (which incases the conductor wires),'it necessitates great care, time and patience in accomplishing the same, owing to the fact that the cord has to be. twisted into and out of the threaded head or collar of the plug. This will, in some instances, disarrange the terminals (which are soldered or otherwise secured to the wires.) Furthermore, the threads will tendto cut the braid-,

ed casing, and in this way the braided cord will become considerably worn. The object of the present invention is to obviate these ,above features and disadvan tages, by providing a two part plug head,

one of the parts forming an integral connection with the plug, while the other part is detachable and constitutes a clamp. In attaching the braided cord to this form of plug head, the cap or clamping part is first removed, then the braided cord is placed in the other part, after which the clamping part' or cap is replaced, there being screws passing through'ears of the clampingpart, for holding the same to the other part. The two parts of the head are provided with ointed spurs or teats upon their inner surface to embed in the braided cord, to prevent the same from slipping.

One of the features of the invention is the provision of a tongue and groove connection between the two parts, to hold the two parts in registration, while the screws are being turned home.

In practical fields the details of construc tion may be subject to alterations, falling within the scope of what is claimed.

The invention comprises further features and combination of parts, as hereinafter set forth, shown in the drawings and claimed.

In the drawings: Figure 1 is a view in perspective of a switchboard plug constructed in accordance with the invention. Fig. 2 is on line 33 of Fig. 1.

-ceive the tongues 7 ,'-an

Fig. 1. Fig. 3' is a transverse sectional View Fig. t is.;adetail viewshowing the two parts of the head separated.

Referring more particularly to the drawing's, 1 designates the usual form of switchboard plug, with the exception that the head 2 of the plug comprises two parts 3 and 4, the part 3 having an integral connection as at 5 with the plug proper. The part 3 upon each side is provided with a recess 6, and a tongue 7 and shoulder 8. The part or clamp or cap 4 is provided with ears 9upon theopposite longitudinal edges, which ears are received by the recesses '6, secured in place by the small screws 10. The opposite longitudinal edges of the clamping cap or part 4 are provided with ooves 11 to resupplied with tongues 12 to engage the shoulders 8 of the part 3. These tongue and'groove and shoulder connections acting to hold the two parts in registration while the screws are being.

Patented July 21,1914. I Application filed November 13, 1913. Serial No. 800,730. I l

a longitudinal sectional viewon line 2-2 of pointed spurs or teats 14, these teats 13 and 14 acting to prevent the braided cord from slipping. The points of the teats are not extremely sharp, but are slightly rounded, as shown, so as to not cut, mar or disfigure the cord.

1 From the foregoing .in conjunction with the annexed drawing, it will be noted that there has been devised a simple and effective and efiicient two part head for a switchboard plug, and one which has been found practical, in view of the fact that it obviates the necessity of great care, time and pas tience in attaching and detaching the braidbeing detachably connected to saidintegrally' connected parts and having ears to engage sa d recesses, sard parts being semi-cylindrlcal, and the recesses and ears'conformamazes drical surfaces having a plurality of spurs 10 to prevent the cord from siipping.

In tesfiimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

MARTIN A. JANE .8.

ing to'the cylindrical contour of said; parts, means passing through "61169813 for desachably fastening said parts together, the detscnabie part having its longitudinal edges provided with longitudinal shoulders and tongues corresponding to and adapted to cooperste with the first shoulders and tongues so as to insure the (ietachabie parts against slipping, said parts upon their inner; cylin- Witnesses:

F. W. HABNEss, C. B. SANBORN.

@opies of this PB'IZEDZ may be obcsiuefl for five seats eeeii, by acidressiugg the flommissiomer of Peteutu,

Wsshingyton, 23. $3. 

